Application of Novel Microorganism-Based Formulations as Alternative to the Use of Iron Chelates in Strawberry Cultivation

The strawberry is a low-growing, herbaceous perennial plant, sensitive to iron deficiency. The iron deficiency represents a nutritional disorder, leading to a decreased content of photosynthetic pigments, which determines the yellow color characteristic of chlorotic leaves. Therefore, in calcareous soils, the use of synthetic iron chelate is often mandatory in strawberry cultivation. The employment of novel microorganism-based formulations as alternatives to the use of iron chelates, was evaluated during strawberry cultivation by monitoring the morpho-biometric parameters, chlorophylls, the iron content in leaves and roots, and the Fe chelate reductase activity involved in absorption of iron during the chlorosis event in plants using the strategy I. The experimental design envisaged growing strawberry seedlings on an inert substrate (pumice), irrigated with Hoagland solution iron-free, with a 12 h photoperiod. After 42 days, at the first appearance of chlorosis symptoms, plants were transplanted into a calcareous soil, and after seven days, they were treated, by a single application, with a microorganism-based formulations (MBF), an inoculum (In) of Trichoderma spp. and Streptomyces spp., or Sequestrene (Sq). Strawberry plants were sampled and analyzed at 5, 10, 15, and 20 days from the treatments. The results showed that microorganism-based formulations positively affected the strawberry seedlings, by reducing the chlorosis symptoms, producing comparable effects to the Sequestrene treatment.